77138880 has 224 divisors, whose sum is σ = 301776384. Its totient is φ = 16257024.

The previous prime is 77138837. The next prime is 77138921. The reversal of 77138880 is 8883177.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86919 + ... + 87801.

It is an arithmetic number, because the mean of its divisors is an integer number (1347216).

Almost surely, 2^77138880 is an apocalyptic number.

77138880 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77138880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150888192).

77138880 is an abundant number, since it is smaller than the sum of its proper divisors (224637504).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77138880 is a wasteful number, since it uses less digits than its factorization.

77138880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923 (or 913 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 42.

The square root of 77138880 is about 8782.8742448016. The cubic root of 77138880 is about 425.6877078176.

The spelling of 77138880 in words is "seventy-seven million, one hundred thirty-eight thousand, eight hundred eighty".